I’m posting this to my personal blog (and not to the one I maintain about the Dean campaign) because of its significance to online communities, the impact of the Internet on political activism, and as a watershed event that will likely stand out as the moment the landscape shifted. (Really – I’m trying to keep the advocacy to a dull roar here.)

The background: Scott Heiferman is the guy behind i-Traffic.com, which sold to Agency.com for $15m in 1999. He is now the founder of meetup.com, a conceptually elegant site designed to facilitate face to face meetings among likeminded people. (It’s one of those “I-could’ve-thought-of-that-but-didn’t” ideas.)

Now to the watershed event: last week, more than 500 people turned up for a campaign rally for Howard Dean in Manhattan. The interesting part? The Dean campaign had nothing to do with the event. After 300 had RSVP’d, Dean shrewdly decided to show up and show his thanks. That pushed RSVPs to the stratosphere, and attendance exceeded available space by more than 200 people.

Early evidence that Dean may be a favorite among the politically active Net denizens: Dean’s supporters at meetup.com number nearly 6,000 people nationwide, a number ten times that of the next Democratic candidate. (Sen. Kerry has 600 supporters nation-wide, Sen. Edwards has 400, Rep. Gephardt has 49, Sen. Lieberman and Rep. Kucinich are tied at 27, Rev. Sharpton has 6, and Carol Moseley-Braun has 4.) In fairness to the campaigns, it’s possible (even likely) that they are not steering as much traffic to the meetup.com site to encourage participation which may explain the skewed numbers (see below), but meetup.com is fast becoming a clearinghouse for anyone who wants to get together with like-minded people.

What is most interesting in all of this is that the Dean campaign – an underdog (to put it mildly) when it comes to fundraising – has contracted with meetup.com to share e-mail addresses and start planning official campaign appearances and events. In other words, they’ve outsourced some of the infrastructure of managing volunteer events and rallies – a critical component of a campaign, but one that could easily kill an underfunded and undermanned campaign. The potential upside of all of this is that Dean will leverage a small but sophisticated company (meetup.com has just 11 employees) for potentially enormous impact – all while keeping costs much lower than if they had to build it themselves.

(If you’re interested, you can bypass the NY Times account of the event and go straight to a first-hand report as recounted on the DeanBlog.)